Supernatants from human glioblastoma cell lines suppressed in vitro- generated cellular immune responses. These supernatants contained IL-6 but not other cytokines. Short-term (minutes) incubations of these supernatants with monocytes/macrophages of healthy individuals resulted in decreased IL-12 and increased IL-10 production. When inoculated into mice, the supernatants induced a decrease in IL-12 and an increase in IL-10 production (within 24 hours). These latter results demonstrated in vivo supernatant-induced cytokine shifts across species. HPV-infected women were studied for T helper cell (Th) responses to HPV E6 and E7 peptides, as well as to other immune stimuli. Patients who were HPV- positive with no sign of disease responded to E6 and E7. Patients with cervical dysplasia exhibited reduced immune function in general, and were unresponsive to E6 and E7. The extent of immune dysfunction was related to the extent of cervical dysplasia. Homosexual men who were HPV-positive were also studied for Th function. E6 and E7 responses were observed in patients with anal dysplasia. Immune functional defects were limited to patients who were positive for HIV. These patients exhibited reduced responses in general and were unresponsive to the E6 and E7 peptides.